Pediatric syncope: an investigative dilemma??
Resident Clinical Pearl (RCP) – February 2018
Kalen Leech-Porter R3 FMEM, Dalhousie University, Saint John, New Brunswick
Reviewed by Dr. David Lewis
The case
A 16 year old girl comes in by ambulance, after fainting while singing at church on a Sunday morning. Her vitals are: HR 90, RR 16, Temp 36.5, BP 92/64. O2 Sat 99% on RA. On arrival she is alert and looks well. She explains that she stood up to sing, felt lightheaded and then, soon after, lost consciousness. The paramedic lets you know witnesses say she turned ashen grey and sweaty, and was out for about 2 minutes. She had some ‘seizure like activity for 10 seconds’ with a few twitches in different parts of her body. The patient states she was fully recovered within a few minutes. Family history is unremarkable, with no sudden early deaths. Physical examination is also unremarkable. The nurse rolls in an ECG machine to check her rhythm.
What investigations does she require?
Why It Matters?
Pediatric syncope is very common in the emergency setting, accounting for ~1 % of pediatric emergency visits. Between 15 and 50% of children will have at least one syncopal event in their childhood (peaking in adolescence). – It’s a common problem!
The problem?
Historically, working up pediatric syncope has varied widely. ECG use has been routine and some centers have regularly ordered bloodwork, CTs and even EEGs. This onslaught of testing has led to increased hospital costs, stressful false positives for patients and has not improved patient outcomes. Plus, reading pediatric ECGs can be challenging – see the end of this pearl.
A potential solution
In 2017, the Canadian Cardiovascular Society and Canadian Pediatric Cardiology Association published a position statement on an approach to pediatric syncope¹ Full Article – click here
A thorough history and physical can be sufficient in low risk patients – no investigations are required for many pediatric syncope presentations.
Red flags
- Lack of Prodrome: warm/clammy sensation, lightheaded ness, visual changes. Having a prodrome is the most important factor in benign syncope
- Midexertional syncope; however post exertional syncope (having an opportunity to stop) is typically benign
- Chest Pain preceding the event
- Prolonged loss of consciousness
- Family history of cardiovascular disease/sudden death
- Syncope triggered by loud noise
- New medications (QT prolonging drugs)
- Abnormal physical exam – pathologic murmur, sternotomy scar, neurologic deficits
Red herrings
- Pallor is common in vasovagal events
- Palpitations are common in vasovagal events (although evidence around this not robust)
- Involuntary movement is also common in vasovagal syncope. Benign movements can be a muscle twitch to violent jerks of the whole body
Investigative Algorithm
Figure 1. Pediatric syncope investigative algorithm, adapted from Sanatani et al. (2017)
The Evidence
To create this position statement, the Canadian Cardiovascular Society (CCS) performed a literature review of 4307 references, ultimately including 231 articles for full-text review.
Most of the studies referred to in the article are retrospective reviews. Therefore, recommendations in the position statement were mostly graded as ‘Strong recommendation, low level of evidence’. I found the most compelling evidence against routine ECG was the statement: “The ECG was the only indicator of cardiac disease in 5 of 480 patients (1%) and causality could not be determined”.¹ However, they did not list a reference for this statement and I’m not sure what study they drew this conclusion from. I do feel they make a compelling case against over investigation, but as in many areas of medicine, the evidence could be more robust.
Pediatric ECGs – how to interpret?
The nurse hands you the ECG, what features are worrisome on a pediatric ECG?
See following chart from the CCS¹
Figure 2. Pediatric ECG findings in syncope, adapted from Sanatani et al. (2017)
In summary, red light features should prompt an emergent cardiology referral. Yellow light features should prompt a non-urgent cardiology referral while green light features are normal variants and require no further work up.
Case Resolution
There were no red flags, arguably she requires no investigations, not even an ECG. Of course, clinical acumen trumps guidelines, but at least you will be CCS endorsed if you chose to not do any further investigations.
References
- Sanatani, V. Chau, A. Fournier, A. Dixon, R. Blondin, R. Sheldon. Canadian Cardiovascular Society and Canadian Pediatric Cardiology Association Position Statement on the Approach to Syncope in the Pediatric Patient. Canadian Journal of Cardiology. 2017; 33: 189-198.
This post was copyedited by Kavish Chandra @kavishpchandra
